what is difference between `suspendedTransactionAs...

# exposed

[Animesh Sahu]

what is difference between suspendedTransactionAsync() and newSuspendedTransaction() i know one of them return Deferred and other the direct value. But i see that both of them suspend at the time of call, i.e. if `suspendedTransactionAsync()`suspends at the time of call then what is use of await() on the deferred? Like CoroutineScope.async() doesn't suspend at the time of call but rather when await() is called on that right, so what's difference b/w them(transactions)?

[tapac]

https://github.com/JetBrains/Exposed/wiki/Transactions#working-with-coroutines

[Animesh Sahu]

@tapac its not explained there perfectly, why does suspendedTransactionAsync() suspends, again the library is complex so cannot go one by one to calls... Async things should not suspend since they just launch coroutine, whereas it should suspend when we are waiting for the result in await(), i don't understand its behavior

[tapac]

It suspend on a dispatcher thread and shouldn't block your main thread execution.

[Animesh Sahu]

@tapac why does it suspend?

[tapac]

From documentation:

Because Exposed uses JDBC-api to interact with databases that was designed in an era of blocking apis.

Please note what such code remains blocking (as it still uses JDBC) and you should not try to share a transaction between multiple threads as it will lead to undefined behaviour.

[Animesh Sahu]

val job = async(<http://Dispatchers.IO|Dispatchers.IO>) { // it does not suspend here at this line
    // suspendable tasks
}

hob.await() //it does suspend here and should

[tapac]

It works just like this when you use suspendedTransactionAsync

[Animesh Sahu]

Compiler shows it suspends

[Animesh Sahu]

Ohh got it, it suspend for scope creation not for async execution, its confusing since no definition of methods.

[Animesh Sahu]

Anyways thanks for your valueable time 🙂